Since Scout.com began ranking the nation's best recruiting classes in 2002, Penn State has seen its group of players fall within the Top 25 six times.

While some of Penn State's classes have been recognized as top-tier, others have not. Regardless, the program has still found a way to win 98 games since 2002 with the players they had—even if the NCAA refuses to recognize them.

This list was not based on national recruiting rankings at the time the players signed their letters of intent. It wouldn't make sense to do it this way, since the rankings aren't indicative of how the players panned out.

Instead, the classes were judged by the contributions each player made at Penn State over the course of their career. The more key players, they higher the ranking.

Here are the Nittany Lions' five best recruiting classes of the BCS era.

5. Class of 2011

Some of the best players from the past few seasons have come from the 2011 class.

The obvious star here is wide receiver Allen Robinson, who had back-to-back 1,000-yard seasons the past two years. 2013 was his last season in Happy Valley, as the junior opted to head to the NFL draft.

After redshirting in 2011, defensive end Deion Barnes had a breakout year in 2012. He tallied five sacks, 10 tackles for loss and three forced fumbles in route to being named the Big Ten's Freshman of the Year.

Running back Bill Belton and safety Adrian Amos have both played since their true freshman seasons. Belton's big year came last year, when he rushed for 803 yards and five touchdowns. Amos has been an anchor in the secondary his whole career, accumulating 107 tackles and 4 interceptions.

Donovan Smith has been the starter at left tackle since 2012, and tight end Kyle Carter has been another top target for Penn State's quarterbacks.

Defensive lineman Anthony Zettel, linebacker Ben Kline and kicker Sam Ficken are some other players of note from the class.

3. Class of 2006

This class was anchored by a trio of All-Americans on defense. The performances of Jared Odrick, NaVorro Bowman and Aaron Maybin were all recognized nationally. Both Bowman and Maybin would parlay that success into an early NFL career.

On offense, Evan Royster was the gem of the 2006 class. He wound up setting the school record for rushing yards in a career with 3,932.

A.J. Wallace and Maurice Evans both played from the start. Wallace was part of a rotation in the secondary, accumulating 95 tackles in four years. After a sophomore season in 2007 that saw him record 12.5 sacks, Evans' career went downhill after being charged with possession of marijuana.

The rest of the class was rounded out by players like defensive tackle Ollie Ogbu and wide receiver Brett Brackett, both contributors on their respective sides of the ball.

However, this class did have its busts. Highly-touted offensive lineman Antonio Logan-El left the team after a year, and heralded in-state quarterback Pat Devlin eventually transferred. Abe Koroma, Phil Taylor and Chris Bell were all dismissed from the program at some point.

2. Class of 2005

Williams was one of the biggest recruits in school history. An asset at receiver and in the return game, he tallied 2,337 yards from scrimmage and 22 total touchdowns in four years.

Lee continued the tradition of "Linebacker U". He ended his tenure fourth in school history with 325 total tackles.

Clark made the most of his opportunity when it came. The starting quarterback in 2008 and 2009, Clark threw for 5,595 yards and 43 touchdowns over that span. He led Penn State to the Rose Bowl in 2008.

Kicking his way into the record books, Kelly graduated as the school's leader in points with 425. As a freshman, he kicked the game-winning field goal in the 2006 Orange Bowl over Florida State.

King played both offense and defense in 2005, before being moved strictly to cornerback. He saw constant playing time before leaving for the NFL after his junior year.

Scirrotto and Landolt were mainstays in the lineup. Both were three-year starters for the Nittany Lions—Scirrotto at safety and Landolt on the offensive line.

Of the group, Williams, Lee and Landolt were all tabbed as All-Americans.

Among the rest of the class, Mickey Shuler was a valuable asset at tight end and on special teams. The trio of Jerome Hayes, Lydell Sargeant and Knowledge Timmons all contributed on the defensive side of the ball.

1. Class of 2004

Connor was the best player in Penn State's 2004 class. He made an immediate impact, finishing second on the team in tackles in 2004. Connor left Penn State with a school-record 419 tackles, and was an All-American in both 2006 and 2007.

On offense, Jordan Norwood had a very productive career. Over the course of four years, he tallied 158 receptions for 2,015 yards and 13 touchdowns. He was a member of one of Penn State's best receiving corps.

Gerald Cadogan, Rich Orhnberger and A.Q. Shipley combined to start 98 games on the offensive line. On defense, Tyrell Sales and Mark Rubin collectively made 44 starts. Josh Gaines finished his career with 8.5 sacks.

Anthony Morelli didn't pan out to play like the 5-star prospect he was rated as by Scout.com. Notwithstanding, he still led Penn State to two bowl victories and at the time was the only Nittany Lion quarterback to pass for at least 2,000 yards twice.

Deon Butler walked-on at Penn State, but was eventually given a scholarship. He worked his way up the depth chart and into the Penn State record books. Butler finished his career with 179 receptions, the most in Penn State history to date.

Along with Connor, Orhnberger and Shipley were also named All-Americans during their Penn State careers.